What Is Cordocentesis Test?
- Cordocentasis test is a blood test used as a prenatal diagnostic test for detecting suspected genetic abnormality, blood disorder or infection in the fetus. Fetal abnormality such as Down’s syndrome, sickle cell anemia, cleft palate etc can be detected with this test.
- This test is also called percutaneous umbilical cord blood sampling (PUBS). It is an invasive procedure in which blood is obtained from the umbilical cord of the fetus for detailed analysis.
- Cordocentesis is usually performed from 18 weeks to 24 weeks of gestation. The umbilical cord is fully developed by this period. Umbilical cord acts as a link between the mother and infant. All the nutrition from mother to fetus is provided through umbilical cord.
- In earlier days doctors used to rely on cordocentesis as other less riskier tests such as amniocentasis and chorionic villi tests were not available.
- In this test, a needle is inserted into the umbilical cord guided with the help of ultrasound through the abdomen. Blood is collected in the syringe attached to the needle and sent for analysis in a laboratory.
- Beside its use as a prenatal diagnostic technique, cordocentasis is also used as a medium to deliver blood transfusion and medicine to the fetus.
When Is Cordocentesis Performed?
- The purpose of performing cordocentesis test is to confirm certain genetic conditions and blood disorders in the fetus suspected by the doctor in prenatal ultrasound test.
- It helps to detect genetic disorders such as Down’s syndrome or blood disorder such as sickle cell anemia or any infection in fetus. Infection such as toxoplasma and rubella can be detected with its help.
- It gives the choice to abort if there is any serious anomaly or defect in the growing fetus.
- Cordocentesis is also used to deliver blood transfusion and medication through the umbilical cord.
- The procedure is performed between 20 weeks and 24 weeks of pregnancy. During 24 weeks of gestation the procedure is performed in Operation Theater of the hospital as there is more risk of complication which may need urgent cesarean section.
- Today cordocentesis is less performed because of its higher risk of complications. Less risky methods such as amniocentasis and chorionic villi biopsy are used to detect abnormalities in fetus. Nowadays cordocentesis is only performed when other mentioned tests do not provide precise diagnosis.
Complications Of Cordocentesis
Any invasive test has more risk than non invasive technique. Same is true with cordocentesis test. However, it is potentially more risky than other tests such as amniocentesis and chorionic villi test. Below are important complications:
- Bleeding in fetus
- Hematoma in the umbilical cord.
- Slowdown of fetal heart rate.
- Infection in the uterus or fetus.
- Bleeding in the pregnant women.
- Premature rupture of membrane.
Procedure For Cordocentesis Test
- Usually cordocentesis test is carried out between 20 and 24 weeks when the umbilical cord is fully developed.
- The mother is advised to lie down on her back.
- After all aseptic measures and cleansing of the abdomen, a thin needle is inserted into the abdomen guided by ultrasound. Once the needle reaches the umbilical cord, blood is collected in the syringe attached to the needle.
- During the procedure the mother may experience some discomfort. Thus she is advised to take rest for few hours after the procedure in the hospital.
- The collected blood sample is then sent to the laboratory for detailed analysis as needed by the doctor.